原发性肾上腺淋巴瘤的CT和MRI特征

CT and MRI features of primary adrenal lymphoma

目的探讨原发性肾上腺淋巴瘤的CT和MRI特征，以提高对这种罕见病变的认识。方法回顾性分析经病理证实的原发性肾上腺淋巴瘤5例，其中3例同时行MR和CT检查，2例仅行CT检查，观察其CT和MRI表现。结果单侧2例、双侧3例，共8个肿瘤。肿瘤最大径6～15cm，呈圆形2个，椭圆形3个，不规则形3个。行MRI冠状面检查的6个肿瘤中4个呈三角形。与正常肌肉相比，CT平扫2例呈稍低密度，6例呈等密度。MR平扫2例T，WI呈等信号，4例呈稍低信号；T2WI均呈高信号。增强扫描，轻度强化6个，中度强化2个。肿瘤内部强化均匀者2个，稍不均匀者4个，不均匀者2个。4个肿瘤伴同侧肾脏和血管的累及，其中3个肿瘤最大径〉10cm，表现为肿瘤包绕肾上极、肾门或相邻的血管。结论原发性肾上腺淋巴瘤多表现为肾上腺区较大的软组织肿块，增强扫描轻度强化，肿瘤大者易包绕同侧肾脏和相邻血管。

Objective The purpose of this study was to analyze CT and MRI findings of primary adrenal lymphoma in order to enhance the understanding of this rare disease. Methods A group of 5 patients with pathologically proven primary adrenal lymphoma were reviewed. Imaging findings （ CT ＆ MRI, n = 3 ; only CT, n = 2 ） were analyzed and correlated with clinical and pathologic findings. Results There were a total 8 lesions in 5 patients. The maximum diameter of the lesions ranged from 6 to 15 cm. Of the 8 lesions, 2 were round, 3 were oval and 3 were irregular. On coronal MRI, 4 of 6 lesions manifested as triangular. Compared to normal muscle, 2 lesions manifested as slight low-density and 6 lesions manifested as isodensity on unenhanced CT images; 2 lesions showed isointensity and 4 revealed slight hypointensity on Tl WI, all of 6 lesions exhibited hyperintensity on T2WI. After intravenous injection of contrast media, 6 lesions enhanced slightly and 2 lesions enhanced moderately on CT and MRI. 2 lesions were homogeneous, 4 lesions were slightly uneven and 2 were heterogeneous on enhanced CT and MRI. Four lesions infiltrated the ipsilateral kidney and adjacent blood vessels. The maximum diameter 〉 10 cm were seen in 3 of the 4 lesions. These lesions embedded the upper kidneys, renal hilars and adjacent blood vessels. Conclusions Most of the adrenal lymphoma manifested as large soft tissue masses with slight contrast enhancement. The larger lesions were likely to invade the ipsilateral kidney and adjacent blood vessels.